cron_mbt

a simple and fast cron expression parser and scheduler written in MoonBit. created for the 2026 OSC Track 1 MoonBit Competition.

features

• parses standard 5-field cron expressions
• supports macros like @hourly, @daily, etc.
• calculates the next execution time based on current time
• lexer and ast based, zero dependencies

usage

add to moon.mod.json:

{
  "deps": {
    "cxh0404/cron_mbt": "0.1.0"
  }
}

simple parsing and matching:

let expr = @cron.parse("*/5 8-10 * * 1-5").unwrap()

let is_match = expr.matches(
  minute = 15,
  hour = 9,
  day_of_month = 10,
  month = 6,
  day_of_week = 3
)
// true

getting next execution time:

let expr = @cron.parse("@hourly").unwrap()
let current_time = { year: 2026, month: 6, day: 10, hour: 9, minute: 14 }
let next_trigger = expr.next_time(current_time).unwrap()
// 10:00

dev

run tests:

moon test

license

Apache 2.0